Many building structures (residential, commercial and industrial buildings) comprise an inherent ventilation system for providing fresh air to various zones throughout the structure.
Typical building structures cannot rely on the natural flow of fresh or treated air throughout the structure to provide for proper ventilation. Construction techniques and materials have advanced to the point where buildings have become tighter and better sealed against the unintentional ingress of outdoor air and gases and the egress of internal air or other gases.
The principle way to ensure adequate ventilation within a building structure is to install a ventilation system. Usually, such a ventilation system comprises of an array of ventilation shafts (or ducts) and inline fans (having motorized impellers) which together are used to transport fresh, heated, cooled, filtered or treated air from an inlet supply to various regions or zones of the building structure.
As building structures vary substantially in size, different types of ventilation shafts have been designed to handle suitable amounts of air for a given application. Many factors (such as size of the building structure, number of residing people, exterior climate, etc.) result in the ventilation shafts and inlet supply elements, or conduits, having a number of different diameters corresponding to the needs of the building structure. Conduits are typically available with diameters ranging from 4 inches to more than 18 inches. Corresponding inline fans have a variety of requirements with respect to the movement of the air mass.
Inline fan housings and motorized impellers are typically sized to match the conduits they are connected to and as a result, a variety of inline fan housing sizes and motorized impellor sizes exist, each for use in specific applications.
A typical inline fan housing assembly has a fan housing comprising an inlet housing and an exhaust housing each comprising a port of a suitable diameter to connect with the corresponding conduit. A motorized impellor is mounted within a cavity defined by the housings for drawing air in through the inlet port and pushing air out through the exhaust port. Inline fan housings have been sized to correspond with the varying diameters of conduits with which they interface as well as the impellers which they house. Impellor diameter may also vary depending on the application and diameter of the conduits that the ventilation system employs. The inlet housing and exhaust housing may be a single housing referred to as the fan housing.
As various building structures utilize conduits having a number of different diameters and various lengths, it is necessary to have a large variety of inline fans available to properly effect each application. Storing, carrying and transporting a large number of inline fans is costly and requires a warehouse, transportation equipment such as trucks and/or vans and manpower.
Therefore, there is a need to alleviate the requirement of maintaining a large number of different sized motorized impellors and fan housings for each application.